01_Constant Data Memeber

Const in oop

Const Data Members

Defination

The data members,state or properties whose value can not be changed during execution time and require value at time upon intialization .

Note

You can not leave const memmber uninitialized,otherwise it will cause error!

Ways to declare and initialize

1. Initializing at the time of declaration. But keep in mind that some compilers do not allow initialization of 'const' in this way.

2)Initializing in Initializer list of constructors

Example Code

#include<iostream>
using namespace std;

class Student
{
	String name;

	// 1) initializing const member at time of creation
	const int Id=1;
	const double CNIC;

public:
	// 2)initializing const member in member initialization list
	Student():CNIC(123-456789-123) {}

};